Snow Peas in Zone 8A — Pacific Northwest

Snow peas are a fantastic addition to any Pacific Northwest garden. Their crisp, sweet pods are delicious raw, stir-fried, or added to salads. The satisfaction of harvesting these tender treats from your own backyard, especially after our overcast spring days, is hard to beat.

While our mild summers and wet springs can present challenges like late blight, snow peas are a cool-season crop that thrives here with proper timing. Our long 203-day growing season gives you ample opportunity to enjoy multiple harvests.

You can transplant snow peas outdoors from mid-March through early April. Start seeds indoors a few weeks prior if you prefer transplants. Remember to harden off your seedlings for about a week before planting. Gradually expose them to outdoor conditions to avoid shocking them.

Space transplants 3-4 inches apart in well-drained soil. Keep an eye on the weather forecast, as we can still get unexpected cold snaps during this time. Protect young plants with row covers if necessary.

Direct sowing is the preferred method for snow peas, and it works beautifully in our climate. You can sow seeds directly into the garden from late February through late August. For a fall harvest, plant from mid-August through mid-September.

Prepare the soil by loosening it and adding compost or other organic matter. Sow seeds 1 inch deep and 3-4 inches apart. Keep the soil consistently moist until germination. Snow peas, like garden peas, prefer cooler soil, so early spring planting is ideal.

Snow peas need consistent moisture, especially during flowering and pod development. Our dry summer months mean you'll need to pay close attention to watering. Aim for about 1 inch of water per week, either from rainfall or irrigation.

Use the "finger test" to check soil moisture: stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases in our sometimes humid springs. Overhead watering is generally fine during our dry summer months.

Signs of underwatering include wilting leaves and stunted growth. Overwatering can lead to yellowing leaves and root rot. Mulching around the plants with straw or compost helps retain moisture and suppress weeds, which is especially helpful during our dry summers.

Snow peas are vining plants and require support to grow properly. A simple string trellis or netting works perfectly fine, as their vines are lighter than those of snap peas. Install the trellis at planting time to encourage upward growth from the start.

Gently guide the tendrils towards the support as they grow. This helps the plants climb and maximizes air circulation, reducing the risk of fungal diseases.

You can expect your first harvest of snow peas from late April through early November, about 55 days after planting. The key is to harvest when the pods are flat and you can just barely see the pea outlines inside. The pods should be translucent and crisp.

Gently snap off the pods from the vine, being careful not to damage the plant. Regular harvesting encourages continued production. As our first frost approaches in late October, harvest any remaining pods, even if they are a bit smaller. They'll still be delicious!

Here are some common problems you might encounter growing snow peas in the Pacific Northwest:

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves, stems, and sometimes fruit. Leaves curl, yellow, and die. Reduces plant vigor.
• What causes it: Various fungi that thrive in warm days, cool nights, and moderate humidity. Dry leaf surfaces actually favor it (unlike most fungi).
• How to fix/prevent it: Improve air circulation through spacing and pruning. Remove affected leaves. Neem oil or potassium bicarbonate sprays help. Milk spray (1 part milk to 9 parts water) is surprisingly effective. Plant resistant varieties.

Pea Aphids

• What it looks like: Small, soft-bodied green insects clustered on stems and leaves, causing distorted growth and sticky honeydew.
• What causes it: Aphids thrive in mild weather and can quickly multiply, especially during our long, mild fall.
• How to fix/prevent it: Blast aphids off plants with a strong stream of water. Introduce beneficial insects like ladybugs and lacewings. Insecticidal soap can be effective.

Root Rot

• What it looks like: Yellowing leaves, stunted growth, and mushy, brown roots. Plants may wilt even with adequate watering.
• What causes it: Overly wet soil and poor drainage, which are common during our wet springs. Various soilborne fungi.
• How to fix/prevent it: Improve soil drainage by adding compost and avoiding overwatering. Plant in raised beds if necessary. Ensure good air circulation.

Fusarium Wilt

• What it looks like: Wilting on one side of the plant first, then spreading. Yellow leaves starting on one side. Brown streaks in stem when cut open.
• What causes it: Soil-borne fungus (Fusarium oxysporum). Persists in soil for years. Enters through roots. Warm soil temperatures favor it.
• How to fix/prevent it: No cure once infected — remove and destroy the plant. Plant resistant varieties (look for 'F' on seed labels). Rotate crops on a 4-year cycle. Solarize soil in hot zones. Raise soil pH above 6.5.

Pacific Northwest Specific Challenges: Late blight is less of a concern for snow peas compared to tomatoes, but it's still something to be aware of, especially during wet springs. Slugs can be a nuisance, especially for young plants, so use slug bait or other control methods. The cool soil in spring can slow germination, so consider starting seeds indoors for an earlier start.

Companion planting can help your snow peas thrive. Carrots and radishes loosen the soil, benefiting snow pea root growth. Cucumbers and corn provide natural trellises for the vines to climb. Lettuce provides ground cover, suppressing weeds and retaining moisture.

Avoid planting snow peas near onions and garlic, as these can inhibit their growth. By choosing the right companions, you can create a thriving and productive garden ecosystem.